e87cd7e380
Remove ExplicitSelf from HIR `self` argument is already kept in the argument list and can be retrieved from there if necessary, so there's no need for the duplication. The same changes can be applied to AST, I'll make them in the next breaking batch. The first commit also improves parsing of method declarations and fixes https://github.com/rust-lang/rust/issues/33413. r? @eddyb